Electro-Chemo-Mechanical Model for the Damage in Porous Electrodes of Lithium-Ion Batteries

Abstract

An electro-chemo-mechanical model is developed for lithium-ion battery (LIB) considering the damage of active material (AM) particles. The established model is used to evaluate the effect of stress and the effect of damage on the electro-chemo-mechanical behavior of cathode. Computational results suggest that moderate stress is beneficial for the battery performance, while damage generated by high stress can considerably degrade the battery capacity. Three ways to model the structure of electrodes are compared. The ordered stacking particles lead to an underestimation of battery performance, while the nonoverlapped random stacking particles lead to an overestimation of battery performance. The impact of several structural factors on the electro-chemo-mechanical behaviors of LIB is investigated in detail. Smaller particle size is beneficial for the battery performance. Furthermore, an increasing particle size from the separator to the current collector leads to higher capacity compared with decreasing gradient or no gradient. The fundamental understanding of electro-chemo-mechanical behaviors of LIB can benefit the design of novel electrodes with more stable performance and a longer lifespan.